This invention relates generally to connector devices for printed circuit board assemblies, and, more particularly, to an isolator device for isolating high voltage power supply contacts from lower voltage electronic circuitry, such as those found in electronic electricity meters.
Conventional electrical metering systems include a plurality of electrical meters, such as induction or electronic type watthour meters, for measuring the energy consumption of individual electrical energy users. Each electronic type meter generally includes metering circuitry for measuring the power consumption of the electrical load associated with the meter and for tabulating the load data related to the measured power consumption. The metering circuitry of conventional electrical meters generally includes an internal current sensor mounted within the housing of the electrical meter for sensing the line current supplied to the associated electrical load and for producing an output signal related to the line current.
To ensure accuracy of the meter, at least some types of electronic meters include a revenue guard board that monitors a single phase of a three phase power supply for voltage and/or current sensing. When the monitored phase of the three phase power supply is interrupted, the revenue guard circuitry then monitors another of the three phases of the three phase power supply so that the meter continues to measure power consumption even when one of the three phases of the power supply is interrupted. Typically, such revenue guard boards are directly coupled to the electronics of the meter, such as a microprocessor, other option boards, and other electronic components of the meter. This construction can be problematic, however, in that the revenue guard board operates at high voltage in comparison to the electronics of the meter, thereby requiring proper space allocation of the high and low voltage components and increasing a required size of the meter to accommodate the respective electrical components.
Furthermore, a variety of connectors have been employed to isolate high voltage power supply contacts, such as the power supply contacts in the meter, from each other and from lower voltage contacts and components in the meter electronics. During normal operation of the meter, the high voltage power supply contacts are vulnerable to voltage excursions due to lightning and switching transients occurring throughout the power distribution system. Without a high level of isolation between power supply contacts, undesirable arcing can occur. Aside from property damage and safety issues, this exposure of the power supply contacts may compromise proper meter operation, the life span of the meter and reliability of the meter.
In one aspect, a voltage isolator connector is provided for a printed circuit board. The connector includes an end wall; a first side wall extending from the end wall, and a second side wall extending from the end wall. The first and second side walls form an isolator compartment with the end wall, and the end wall and the first and second side walls are configured for attachment to the printed circuit board.
In another aspect a printed circuit board assembly includes a printed circuit board including opposite first and second surfaces, a plurality of high voltage contacts extending from the first surface, and an opening through the board. A voltage isolator connector is configured for insertion though the opening and forming at least one isolator compartment about at least one of the high voltage contacts when the connector is partially inserted through the opening. The voltage isolator connector is further configured for locking engagement with said printed circuit board at opposite ends of the connector.
In another aspect, a meter includes a base module comprising power supply leads and a power supply connector and at least one printed circuit board for connection to the power supply leads. The printed circuit board comprises at least first and second surfaces, at least one power supply contact, and an opening through the board. A voltage isolator connector is partially inserted through the opening and forms an isolator compartment about the at least one power supply contact, and a power supply connector is inserted over the voltage isolator connector to establish an electrical connection with the at least one power supply contact.
In another aspect, a method is provided for establishing an electrical connection between a three phase power supply and a printed circuit board including a plurality of power supply contacts. The method employs a voltage isolator connector having an open end and at least one isolator compartment formed into the open end, and the printed circuit board includes an opening adjacent the plurality of power supply contacts. The method comprises the steps of inserting the open end of the voltage isolator connector through the opening of printed circuit board such that the voltage isolator connector extends partially through the opening, and securing the voltage isolator connector in position relative to the board such that the at least one isolator compartment isolates at least one of the power supply contacts from another of the power supply contacts.